Discover the Largest House in South Dakota at 13,000 Square Feet

The designation of largest house in South Dakota is up for grabs for those who like to argue technicalities. Generally speaking, the largest fully private, single-structure residence in the Mount Rushmore state is a 13,000-square-foot mansion in Sioux Falls. This largest house in South Dakota has 11 bathrooms, seven bedrooms, and—most importantly—a working skeeball machine.

Two other residences in the state that could beat it are on this list, but it’s a tough call. (We’ll explain).

The Swinged Cat State and Housebuilding

On a map, South Dakota looks like a great place for an architect to build something. Though there are canyons, the Black Hills, and one very famous mountain statue, there’s a lot of flat land in the east of the state. The houses may be new, but the state itself has many older cities.

And indeed, it’s surprisingly low-cost to build a house there. According to the sell-by-owner real estate platform Houzeo, it’s about $102 per square foot ($81,600 for 800 square feet and $510,000 for 5,000 square feet). This price makes it at or near the lowest cost in the US, $100 per square foot.

That affordability was a significant factor for the Baumgarten. The owners of the Sioux Falls manse left a 611 square-foot apartment in Manhattan for the roomy prairie lands in eastern South Dakota.

The Winner Overall for Largest House in South Dakota

This home doesn’t have a real estate listing, but we can take the words of the Wall Street Journal who covered it.

Keith Baumgarten is not a tech executive, CEO, or influencer. He’s a skilled orthopedic specialist. His wife, Sara, is a business consultant and property manager in charge of several rentals in South Dakota’s biggest city, Sioux Falls. Still, they have an extremely large home.

Altogether, they spent $3.25 million on the house they have today.

Biggest Single-Building Private Home in South Dakota

• Baumgartens bought a home near downtown for $2.05 million in 2009 and did a $1.2 million reno
• They brought in specialist decorators and home designers
• Their four children are home-schooled and share Keith’s office
• The outdoors has a climbing wall and in-ground pool
• A theater stage in the basement is where the family plays classical guitar
• The guest house has bunk beds for kids
• The basement has 12-foot ceilings!

The home was widely reported as 13,000 square feet overall. The basement alone, apparently not included in the size, is 4,000 square feet!

It sounds like they put a lot of time, effort, and planning into the home. We probably won’t see this largest house in South Dakota on Zillow anytime soon.

Two Residences, Same Property; 15,000 Square Feet

A six-bedroom, five-bathroom estate property in Castlewood, SD, is available. A primary real estate website has it as almost exactly one year on the market. And at 15,000 square feet, it’s a steal for $575,000.

The listed square footage is 15,000. Aerial photos also show a host of accompanying buildings—listed as plane hangars—on the 2.84 acres. All that is in addition to an attached garage and an enormous shed-roof bonus detached garage.

The primary residence has a three-floor turret with two wrap-around balconies.

Anyone can make a house this size work. But there’s a catch: reading closer, it’s actually two buildings comprising 15,000 square feet of residential space. It has a bigger overall footprint and one address, but it’s technically two dwellings. Still, I don’t think anyone would complain.

The New Governor’s Mansion; 14,000 Square Feet but Technically a Civic Structure

At 14,000 square feet, the current South Dakota governor’s mansion is close to the top for the largest house in South Dakota. And completed in 2005, it’s likely near the top of the list for the newest governor’s mansion in the US.

There was no official governor’s mansion in South Dakota until 2005! Yet, the keyword there is “mansion.” From 1937 until then, the governor’s residence was a revamped cottage in the capitol city of Pierre (it was still a generous 7,000 square feet). And before that, the state budget gave the governor $75 per month residence stipend, expecting they’d figure it out.

Construction began on the current South Dakota governor’s mansion in the spring of 2004 and was completed the following year. There’s a carport awning, Victorian lampposts, a circular mezzanine balcony with a brilliant chandelier, a very nice pond, and a sizable lawn. All this comes in handy with the governorship’s entertaining duties: the home can apparently accommodate 100 dinner guests.

The Largest Houses in South Dakota Are Big and Bold

The Mount Rushmore state has some monumental-sized houses.